Particularly this piece of news seems toxic to me, as selling energy to other markets is an obvious response.
Power prices going negative is a failure state not "good news" because it implies that active protection of other generators economic viability is being exercised to protect against externalities - i.e. your gas fired peakers can't make any money during the day, but when the solar goes off at night you still need them. Therefore, the gas fired peakers have to be sponsored to continue existing to service the demand at other times.
They don't need sponsoring, if they're needed at night then the nighttime energy prices will reflect the costs including the downtime. Which is then a business opportunity for storage technologies to become feasible.